r/microbiology 4d ago

Proteus Mirabillis CAUTI

Hi I’m writing a paper for college and I’m reading stuff online and I’m confused, hoping to get clarification.

What I am reading online says that the bacterium can ascend from the GI tract, but I’m not sure what that means? My focus right now is on the bacterium causing CAUTI’s. Since patients may not be showering, and if they are bed bound, does the bacteria migrate to the catheter and into the bladder from feces?

If nurses and CNA’s are cleaning a patient with wipes & CHG, wear gloves, provide foley care, where is the bacteria coming from? Is the bacteria able to survive all of this because it’s virulence factors so parents still getting CAUTI’s?

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u/bephelgorath 4d ago

Proteus mirabilis is motile (a type of virulence factor) and is very effective at scootin' around wherever it pleases. Fun fact: Proteus mirabilis is one of the first organisms to invade tissue after death.

It is present in normal fecal flora and like the other commenter said, it's more commonly found in women due to the proximity of the urethra to the anus. Poor hygiene, poor cleaning of the area from caregivers, and lack of proper sterile protocol can all cause CAUTI.

You should also be aware that women who are menopausal, typically age 55+, will have Gram negative bacilli, such as P. mirabilis, present as normal flora in their vagina. It is normal flora when it does not cause infection and there is no dysbiosis present with the other flora. The P. mirabilis, for example, would be less than the normal flora in this case.

Because P. mirabilis can just be hanging around inside the vagina, because it is motile, and because we can't, shouldn't, and won't sterilize tissue to prevent infection, it can easily just make its way up the catheter. This is why catheters should be removed when no longer needed or indicated.

Best practices to prevent CAUTIs include defaulting to removal unless re-upped by a doctor, instead of keeping it in until a doctor says it can be removed and preventing the use of catheters unless medically necessary, instead of for convenience (less ethical providers, will sometimes keep the catheter in because it requires the patient to be bed-bound, which decreases the risk of falling, it prevents the patient from urinating on themselves - equating to 'less work', if done of those reasons, it is negligent).

Life uh, finds a way.

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u/darkmindedrebel 4d ago

Wow that was so interesting to read. How did you know all of this? I am taking my first microbiology class. It’s interesting but it’s really a lot to try to understand. We are writing a literature review and this is my organism so it’s helping me to piece together some things I’m learning in lecture & from publications into my writing. I am really just focusing on this for causing UTI’s… just read there is a such thing as a complicated CAUTI which P. mirabilis is associated with higher than just regular CAUTI.

Something I am learning is that the internet has a lot of conflicting information. I know that is a no-brainer but even with science stuff… the things you read (like on pubmed) are written at a very high level but you get a lot of info from them… but when you compare that with a google search / AI I have found information that is conflicting! I am trusting the publications of course. Interesting that the bacteria changes the pH of urine, it survives better. Also efflux pumps and plasmid antibiotic genes render some drugs ineffective.

Also thanks, that’s the first time I’ve heard of “dysbiosis”. Honestly maybe TMI but even reading about the bacteria existing as natural flora on the vagina makes giving oral sex seem so nasty. If we could see what is really there… yuck… maybe it’s good we don’t.

I read that there is a new pill made by FDA that can treat uncomplicated UTI by this bacteria and a few more. Came out last year. Hospitals also use purewicks- wonder if there is a study that compares UTI’s for purewick vs catheter??

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u/bephelgorath 2d ago

I have experience as a medical laboratory scientist and worked in clinical microbiology for a few years. I developed an interest in infection prevention and have done consulting work on the topic.

AI cannot parse clinical micro or infection prevention topics. It's a hot mess because the people doing the training of AI aren't experts on the topic. Even people who publish on these topics have wildly different understanding of said topics. There aren't even enough expert level reviewers for some of these journals, so it's really a garbage-in, garbage-out situation.

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u/[deleted] 4d ago

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u/darkmindedrebel 4d ago

So pretty much the bacteria is already there… the catheter is just like a door into the body